Validity and Reliability of New Standard for Resting fMRI Data

描述（由申请人提供）：静息状态功能磁共振成像（R-fMRI）和内在功能连接（iFC）映射激发了发育和精神功能神经成像，但对参与者运动和预处理策略对R-fMRI结果的影响的担忧已经开始阻碍该领域的进展。面对过多的回顾性运动校正和干扰信号回归选项，研究人员不确定如何进行。最近发表的方法，多回波独立成分回归（ME-ICR），提供了一个原则和客观的方法来识别和消除运动相关的伪影和其他信号的不感兴趣的R-fMRI数据。这种新颖的方法利用了多回波（ME）采集可用于区分fMRI信号强度（与运动，生理节律和扫描仪相关噪声等干扰源相关）的非BOLD变化与感兴趣的BOLD信号变化的原理，这些变化表现出对回波时间（TE）的依赖性。该原理应用于ME-ICR中，以根据TE依赖性对使用独立分量分析（伊卡）识别的信号分量进行排序，从而将感兴趣的TE依赖BOLD信号与不感兴趣的TE独立非BOLD信号分离。当在35名健康成年人的样本中验证时，ME-ICR表现出增加的时间信噪比，成功去除运动伪影，增加iFC图的特异性，并改善统计推断，相对于传统的分析。虽然引人注目，该方法不仅需要改变分析程序，而且在数据采集（从单次到ME）。在没有确凿证据证明ME-ICR方法适用于临床人群的情况下，实验室将不愿意采用ME-ICR方法。在临床人群中获取新ME数据集的努力可能需要数年时间。幸运的是，我们的实验室自2009年以来一直使用ME序列。因此，我们建议将ME-ICR应用于我们独特的大型MER-fMRI扫描数据库，这些数据库收集自600多名患有ADHD，自闭症以及典型比较的儿童和成人。我们将研究ME-ICR对R-fMRI测量中年龄和诊断相关差异的估计及其重测信度的影响。通过对ME-ICR量表的信度和效度进行评估， 在现有数据的大样本中，拟议的研究将加速其实用性的证明，并最终采用，为发展和精神病R-fMRI研究。这一提议是及时的，并且可能是变革性的，因为ME-ICR提供的方法学进步将允许该领域超越当前的挑战，从而使R-fMRI能够实现其承诺 作为一种转化方法，忠实地揭示了健康和疾病中的宏观大脑功能。此外，通过允许在个体受试者水平上进行有效的统计推断，ME ICR可以将神经成像推向个性化医疗的目标。最后，通过建议共享ME数据，将在不增加成本的情况下大大增强该项目的科学影响。

DESCRIPTION (provided by applicant): Resting state fMRI (R-fMRI) and intrinsic functional connectivity (iFC) mapping have energized developmental and psychiatric functional neuroimaging, but concerns about the impact of participant motion and preprocessing strategies on R-fMRI findings have begun to stall progress in the field. Faced with a plethora of options for retrospective motion correction and nuisance signal regression, researchers are unsure of how to proceed. A recently published method, multi-echo independent components regression (ME-ICR), offers a principled and objective approach to identifying and removing motion-related artifact and other signals of no- interest from R-fMRI data. This novel method capitalizes on the principle that multiecho (ME) acquisitions can be used to differentiate non-BOLD changes in fMRI signal intensity (related to nuisance sources such as motion, physiological rhythms, and scanner-related noise) from changes in BOLD signals of interest, which exhibit a dependence on echo time (TE). This principle is applied in ME-ICR to sort signal components identified using independent components analysis (ICA) according to their TE dependence, thus separating TE-dependent BOLD signals of interest from TE-independent non-BOLD signals of no interest. When validated in a sample of 35 healthy adults, ME-ICR exhibited increased temporal signal-to-noise, successful removal of motion artifacts, increased specificity of iFC maps, and improved statistical inference, relative to conventional analyses. Although compelling, the approach requires not only a change in analytic procedures but also in data acquisition (from single-shot to ME). Labs will be reluctant to adopt ME-ICR method in the absence of conclusive evidence of its applicability to clinical populations. Efforts to acquire new ME datasets in clinicl populations could take years. Providentially, our lab has used an ME sequence since 2009. We thus propose to apply ME-ICR to our uniquely large database of ME R-fMRI scans collected from over 600 children and adults with ADHD, autism, as well as typical comparisons. We will examine the impact of ME-ICR on estimates of age- and diagnosis-related differences in R-fMRI measures, and on their test-retest reliability. By assessing the validity and reliability of ME-ICR in a large sample of existing data, the proposed study will accelerate the demonstration of its utility, and ultimately, adoption, for developmental and psychiatric R-fMRI studies. This proposal is timely and potentially transformational, since the methodological advances offered by ME-ICR would permit the field to transcend present challenges, thus enabling R-fMRI to fulfill its promise as a translational approach that faithfully reveals macro-scale brain function in health and disease. In addition, by permitting valid statistical inference at the individual subject level, ME ICR can move neuroimaging toward the goals of personalized medicine. Finally, by proposing sharing of the ME data, the scientific impact of this project will be greatly enhanced at no additional cost.